This project applying cognitives in schools with adolescents has four primary aims: 1) to replicate the excellent results found with adolescents who received at school proactive, individualized and interactive multimedia expert systems for smoking, high fat diets and sun exposure. 2) To expand these findings to three additional behavioral risk factors for cancer, namely alcohol abuse, sedentary life-styles and stress; and 3) to enhance our current best practices for smoking, diet and sun exposure by creating an integrated expert system that teaches teenagers the basic principles and processes for changing these and other risk behaviors; 4) to explore the additive effects of treating both students at school and their parents at home (in a parallel Interactive RO1 project entitled "Home Computers for Parents for Six Cancer Risk Factors") compared to treating just the students alone for each of the six target behaviors. This population-based clinical trial employs a 3 X 4 repeated measures design crossing 3 groups (the Best Practices expert systems for smoking, diet and sun exposure; an innovative integrated expert system; and the New Behaviors comparison group that also serves as a distraction placebo control. Fourteen high schools will participate with 3570 ninth graders being randomly assigned to one of the three groups. All participants will receive six 45 minute expert system sessions during their ninth and tenth grades. The expert systems provide normative (compared to their peers) and ipsative (compared to self) feedback on each of the 15 relevant Transtheoretical Model variables for each of their relevant risk factors. These systems are designed to provide guided learning for accelerating and facilitating progress through stages of change. Since nearly 80 percent of eligible students are expected to participate, these programs have considerable potential to produce major population impacts on six of the most important behavioral risks for cancer and other chronic diseases. The project will produce individualized and interactive multimedia computer programs that can be disseminated in a cost-effective manner through schools to help entire populations of adolescents.